The present invention relates to a read-only sequence control system for sequentially controlling manufacturing operations in a factory.
Generally, a compact sequence controller is provided with eight outputs and a cycle time of the operation thereof is about 3 seconds. Further, a large number of sensors are attached to various portions of a machine such as a press in a factory in order to detect abnormalities of products or failures of the machine. Accordingly, the circuit of the controller for the sensors is very complicated.